parser challanging of Xola

C&C++/flex/ill_show_you_xola/171215171604586.c

@@ -0,0 +1,64 @@
+#include <xolatile/xtandard.c>
+#include <xolatile/xyntax.c>
+
+int main (int argc, char * * argv) {
+	int index  = 0;
+	int offset = 0;
+	int length = 0;
+	int select = 0;
+
+	syntax_define (false, true, "Head",   "HCST.", '\\', colour_red,    effect_bold);
+	syntax_define (false, true, "Circle", "HCST.", '\\', colour_green,  effect_bold);
+	syntax_define (false, true, "Square", "HCST.", '\\', colour_yellow, effect_bold);
+	syntax_define (false, true, "Tail",   "HCST.", '\\', colour_blue,   effect_bold);
+
+	for (index = 1; index < argc; ++index) {
+		char * input = argv [index];
+
+		int count      = 0;
+		int token [24] = { 0 };
+
+		for (offset = 0; input [offset] != '\0'; offset += length) {
+
+			select = syntax_select (& input [offset], & length);
+
+			if (select >= syntax_count) {
+				terminal_colour (colour_white, effect_normal);
+			} else {
+				terminal_colour (syntax_colour [select], syntax_effect [select]);
+			}
+
+			out (& input [offset], length);
+
+			terminal_cancel ();
+
+			if (string_compare_limit (& input [offset], "Head",   4) == true) token [count] = 1;
+			if (string_compare_limit (& input [offset], "Circle", 6) == true) token [count] = 2;
+			if (string_compare_limit (& input [offset], "Square", 6) == true) token [count] = 3;
+			if (string_compare_limit (& input [offset], "Tail",   4) == true) token [count] = 4;
+
+			++count;
+		}
+
+		echo (" -> ");
+		for (offset = 0; offset < count - 1; ++offset) {
+			if ((token [offset] == 1) && (token [offset + 1] == 2) && (token [offset + 2] == 4)) {
+				echo ("1");
+				offset += 2;
+			} else if ((token [offset] == 1) && (token [offset + 1] == 3) && (token [offset + 2] == 4) && (token [offset + 3] == 3)) {
+				echo ("3");
+				offset += 3;
+			} else if ((token [offset] == 1) && (token [offset + 1] == 3) && (token [offset + 2] == 4)) {
+				echo ("2");
+				offset += 2;
+			} else {
+				echo ("Invalid tokens...\n");
+				return (log_failure);
+			}
+		}
+		echo ("\n");
+	}
+
+	return (log_success);
+}
+

C&C++/flex/ill_show_you_xola/l.l

@@ -0,0 +1,19 @@
+%{
+    #include "main.tab.h"
+    const char input_str[] = "HeadCircleTailHeadSquareTailHeadSquareTailSquare";
+	const int  len         = sizeof(input_str)-1;
+		  int  offset      = len;
+	#define YY_INPUT(buf, result, max_size) {                        \
+		int cpi = (offset && offset > max_size) ? max_size : offset; \
+		memcpy(buf, input_str+(len-offset), cpi);                    \
+		result = cpi;                                                \
+		offset = (cpi > offset) ? 0 : offset - cpi;                  \
+	}
+%}
+%option noyywrap
+%%
+Head        { return HEAD; }
+Square      { return SQUARE; }
+Circle      { return CIRCLE; }
+Tail        { return TAIL; }
+%%

C&C++/flex/ill_show_you_xola/main.y

@@ -0,0 +1,39 @@
+/*
+  @BAKE
+    bison --header=main.tab.h $@ -Wcounterexamples
+    flex l.l
+    gcc main.tab.c lex.yy.c -ggdb
+    ./a.out
+  @STOP
+*/
+%{
+    #include <stdio.h>
+
+    void yyerror() { ; }
+%}
+%token HEAD CIRCLE SQUARE TAIL
+%%
+
+document: %empty
+    | document number
+    ;
+
+number: one
+    | two
+    | three
+    ;
+
+one: HEAD CIRCLE TAIL           { fputs("1", stdout); }
+    ;
+
+two: HEAD SQUARE TAIL           { fputs("2", stdout); }
+    ;
+
+three: HEAD SQUARE TAIL SQUARE   { fputs("3", stdout); }
+%%
+
+signed main() {
+    yyparse();
+    puts("");
+    return 0;
+}

C&C++/flex/ill_show_you_xola/spec.txt

@@ -0,0 +1,13 @@
+Write a parser that accepts an arbitrary long string.
+The valid keywords are:
+    Head
+    Circle
+    Square
+    Tail
+The following input sequences should yield the following outputs:
+    HeadCircleTail          -> 1
+    HeadSquareTail          -> 2
+    HeadSquareTailSquare    -> 3
+Multiple inputs can be chained together in the input. E.g.:
+    HeadCircleTailHeadSquareTailSquare  -> 13
+Invalid input shall be rejected.